Lifting apparatus



(No Model.) 2 Sheets-Sheet 1. C. SANBORN.

LIFTING APPARATUS.

No. 319,132. Patented June 2, 1885.

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(No Model.) 2 Sheets-Sheet 2.

. C. SANBORN.

LIFTING APPARATUS.

No. 319,132. Patented June 2, 1885.

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UNITED STATES CLARENCE SANBORN, OF SACRAMENTO, ASSIGNOE OF ONE- HALF` TOA. T.

PATENr Eties.

DEWEY, OF SAN FRANCISCO, CALIFORNIA.

Ll FTING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 319,132, dated June 2,1885.

Application filed April 30, 1883. Renewed May 6, 1885. (No model.)

To all whom t may concern:

Be it known that I, CLARENCE SANEORN, of Sacramento, county ofSacramento, State of California, have invented an Improved LiftingApparatus; and I hereby declare the following to be a full, clear, andexact description thereof.

My invention relates to certain improvements in that class of liftingapparatus known as lock-pnlleys;7 and it consists in certain details ofconstruction hereinafter described and claimed.

Referring to the accompanying drawings for a more complete explanationof my invention, Figure I, Sheet 1, is a perspective view of myapparatus. Fig. 2, Sheet 2, is an edge view with chains removed. Fig. 3,Sheet 2, is a vertical section through one of the crank arms or pins andthe main axle, showing a side view ofthe gear-wheels, the nearest onehaving a portion broken away.

A is a frame of any suitable form and size, in which the gear andpulley-shaft B is supported, while below this the cranked driving-shaftC is journaled. Upon the shaft B is xed the chain-pulley I), having itsperiphery formed to receive, in the usual or any suitable form, thelinks of the hoisting-chain E and prevent them from slipping. Upon thesame shaft are fixed the two gear-wheels F F. In the present caseI haveshown. these two wheels placed side by side, with a small interveningspace; but they may be cast in one piece, if desired. It will also beseen that they might be fixed one upon eac-h side of the chain-pulley D;but I prefer the present arrangement as being stronger and moreconipact. These gears are so fixed that the teeth of one stand oppositethe spaces of the other. The shaft C has formed in it two eccentric pinsor short crank-arms, G, which stand upon opposite sides of the axis ofthe shaft, and are of a diameter less than half the diameter of shaft C.The throw of these pins is fixed by the distance between the teeth ofthe gearwheels, with which they correspond, so that as the shaft isrevolved the pins enter the spaces between the teeth alternately, andthus advance them and turn the shaft and hoistingchain pulley. The formof the teeth of the gear-wheels and the spaces between them is shown inFig. 3, and is such that the pins G in their revolution pass over thepoints of the teeth and enter the spaces between them without slip orlost motion, and with the least possible friction. When allowed to standwith a weight suspended from the chain E, the pins G will lie in thespaces between the teeth, so as to form a perfect lock and prevent theshaft from yturning back.

Upon the end of the shaft C is fixed a pulley, H, which is usuallyachain-pulley, with au endless chain, I, passing over it and depending toa point within easy reach of the operator. Guides .I depend fromy theframe A, and the chain I passes through them, and is thus kept inposition upon the pulley when running rapidly. Vhen used with pulleys,as here shown, the frame A is suspended by a hook or otherwise, so as tobe properly balanced. lt will be manifest that this method ofadvancingatoothed surface is not confined to circular gears, but mayalso be applied to straight rack -bars, which would be placed with theirteeth alternating in the same manner, and the shaft with the eccentricpins would engage these teeth, so as to advance them in a similar mannerwith the gears.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

In a lifting apparatus, gears or racks having toothed surfaces placedside by side, so that the teeth of one are opposite the spaces of theother, in combination with a shaft having eccentric pins upon oppositesides of the center and within the diameter of the Shaft, one of saidpins engaging the teeth of each wheel, so that said teeth may passbeyond the center of the shaft, substantially as herein shown anddescribed.

In witness whereof I hereunto set my hand.

CLARENCE SANBORN.

Witnessesz S. H. Nounsr., .IosErn A. BAYLEss.

